/* ====================================================================== iff.c Ernie Wright 18 Apr 98 MSVC 4.0 Save an image in IFF ILBM format. Supports 24-bit color and 8-bit grayscale. ====================================================================== */ #include #include #include #define MAKE_ID(a,b,c,d) ((a)|((b)<<8)|((c)<<16)|((d)<<24)) #define ID_FORM MAKE_ID('F','O','R','M') #define ID_ILBM MAKE_ID('I','L','B','M') #define ID_BMHD MAKE_ID('B','M','H','D') #define ID_BODY MAKE_ID('B','O','D','Y') typedef struct { unsigned short w, h; // image width, height in pixels short x, y; // image position in destination unsigned char nPlanes; // number of bitplanes (depth) unsigned char masking; // mask type unsigned char compression; // compression algorithm unsigned char pad1; // pad char for alignment unsigned short transparentColor; // a logical color number unsigned char xAspect, yAspect; // pixel ratio of width : height short pw, ph; // source page size } BMHD; void rotate8x8( unsigned char *src, int srcstep, unsigned char *dst, int dststep ); void image_progress( int y ); static int writeBMHD( FILE *fp, int w, int h, int nchannels ); static int writeBODY( FILE *fp, char *buf, int w, int h, int span, int nchannels ); static int write_channel( FILE *fp, unsigned char *src, unsigned char *rot, unsigned char *dst, int rowbytes ); static int pack( char *src, char *dst, int rowsize ); static void revbytes( void *bp, int elsize, int elcount ); /* ====================================================================== saveIFF() Save an image in IFF ILBM format. INPUTS filename name of the file to create buf pixels in packed DIB arrangement w, h width and height span number of bytes in one image row nchannels 1 for grayscale, 3 for RGB RESULTS Saves the image. Returns TRUE if successful, otherwise FALSE. ====================================================================== */ int saveIFF( char *filename, char *buf, int w, int h, int span, int nchannels ) { FILE *fp; long ck[ 3 ] = { ID_FORM, 0, ID_ILBM }; int size, ok = 0; fp = fopen( filename, "wb" ); if ( !fp ) return 0; while ( 1 ) { if ( 1 != fwrite( ck, 12, 1, fp )) break; ck[ 1 ] = 4; ck[ 1 ] += size = writeBMHD( fp, w, h, nchannels ); if ( !size ) break; ck[ 1 ] += size = writeBODY( fp, buf, w, h, span, nchannels ); if ( !size ) break; revbytes( &ck[ 1 ], 4, 1 ); if ( fseek( fp, 4, SEEK_SET )) break; if ( 1 != fwrite( &ck[ 1 ], 4, 1, fp )) break; ok = 1; break; } fclose( fp ); if ( !ok ) remove( filename ); return ok; } static int writeBMHD( FILE *fp, int w, int h, int nchannels ) { BMHD bmhd = { w, h, 0, 0, nchannels * 8, 0, 1, 0, 0, 1, 1, w, h }; long ck[ 2 ] = { ID_BMHD, 20 }; revbytes( &ck[ 1 ], 4, 1 ); revbytes( &bmhd.w, 2, 4 ); revbytes( &bmhd.pw, 2, 2 ); fwrite( ck, 8, 1, fp ); fwrite( &bmhd, 20, 1, fp ); return 28; } static int writeBODY( FILE *fp, char *bits, int w, int h, int span, int nchannels ) { unsigned char *mem, *row, *src, *rot, *dst; int pos, i, x, y, n, rowbytes, size = 0; long ck[ 2 ] = { ID_BODY, 0 }; pos = ftell( fp ) + 4; fwrite( ck, 8, 1, fp ); rowbytes = (( w + 15 ) >> 4 ) << 1; mem = calloc( 32 * rowbytes, 1 ); if ( !mem ) return 0; src = mem; rot = src + 8 * rowbytes; dst = rot + 8 * rowbytes; image_progress( h ); for ( y = 0; y < h; y++ ) { row = bits + ( h - ( y + 1 )) * span; if ( nchannels == 3 ) { for ( i = 2; i >= 0; i-- ) { for ( x = 0; x < w; x++ ) src[ x ] = row[ 3 * x + i ]; n = write_channel( fp, src, rot, dst, rowbytes ); if ( n == 0 ) { free( mem ); return 0; } size += n; } } else { n = write_channel( fp, row, rot, dst, rowbytes ); if ( n == 0 ) { free( mem ); return 0; } size += n; } image_progress( 0 ); } free( mem ); if ( size & 1 ) fputc( 0, fp ); ck[ 1 ] = size; size += ( size & 1 ); revbytes( &ck[ 1 ], 4, 1 ); fseek( fp, pos, SEEK_SET ); fwrite( &ck[ 1 ], 4, 1, fp ); fseek( fp, size, SEEK_CUR ); return size + 8; } static int write_channel( FILE *fp, unsigned char *src, unsigned char *rot, unsigned char *dst, int rowbytes ) { unsigned char *p, *q; int i, x, n, size; p = src; q = rot; for ( x = 0; x < rowbytes; x++ ) { rotate8x8( p, 1, q, rowbytes ); p += 8; q++; } p = rot; q = dst; n = size = 0; for ( i = 0; i < 8; i++ ) { size += n = pack( p, q, rowbytes ); p += rowbytes; q += n; } if ( 1 != fwrite( dst, size, 1, fp )) return 0; return size; } static void revbytes( void *bp, int elsize, int elcount ) { register unsigned char *p, *q; p = ( unsigned char * ) bp; if ( elsize == 2 ) { q = p + 1; while ( elcount-- ) { *p ^= *q; *q ^= *p; *p ^= *q; p += 2; q += 2; } return; } while ( elcount-- ) { q = p + elsize - 1; while ( p < q ) { *p ^= *q; *q ^= *p; *p ^= *q; ++p; --q; } p += elsize >> 1; } } #define DUMP 0 #define RUN 1 #define MINRUN 3 #define MAXRUN 128 #define MAXDUMP 128 static int pack( char *source, char *dest, int rowsize ) { char c, lastc; int mode = DUMP, rstart = 0, putsize = 0, sp = 1, i; lastc = *source; rowsize--; while ( rowsize > 0 ) { c = *( source + sp ); sp++; rowsize--; switch ( mode ) { case DUMP: if ( sp > MAXDUMP ) { *dest++ = sp - 2; for ( i = 0; i < sp - 1; i++ ) *dest++ = *( source + i ); putsize += sp; source += sp - 1; sp = 1; rstart = 0; break; } if ( c == lastc ) { if (( sp - rstart ) >= MINRUN ) { if ( rstart > 0 ) { *dest++ = rstart - 1; for ( i = 0; i < rstart; i++ ) *dest++ = *( source + i ); putsize += rstart + 1; } mode = RUN; } else if ( rstart == 0 ) mode = RUN; } else rstart = sp - 1; break; case RUN: if (( c != lastc ) || ( sp - rstart > MAXRUN )) { *dest++ = rstart + 2 - sp; *dest++ = lastc; putsize += 2; source += sp - 1; sp = 1; rstart = 0; mode = DUMP; } } lastc = c; } switch ( mode ) { case DUMP: *dest++ = sp - 1; for ( i = 0; i < sp; i++ ) *dest++ = *( source + i ); putsize += sp + 1; break; case RUN: *dest++ = rstart + 1 - sp; *dest = lastc; putsize += 2; } return ( putsize ); }